1. Field of the Invention
The present invention relates generally to automatic response systems, and more specifically to a multimedia processing system for storing program data and returning stored program data in response to a subscriber's request.
2. Description of the Related Art
Multimedia processing systems are installed in public telephone exchanges as automatic response systems. In a large-scale multimedia processing system a plurality of multimedia processors and a plurality of mass storage units are provided and they are interconnected by a switching hub. A request from the subscriber contains a control signal and a multimedia program signal such as voice, text and facsimile if write mode is requested and contains a control signal only if read mode is requested. One of the processors is selected to process the request. The processed request is applied to the switching hub. When the request is a write mode, both control and program signals of the request are self-routed by the switching hub to one of the storage units according to the address contained in the request and the program signal is stored in the storage unit. When the request is a read command, the control signal of the request is self-routed to the desired storage unit and a scored program is retrieved. The retrieved program signal is self-routed by the switching hub and transmitted back to the selected processor and thence to the requesting subscriber.
Since the program signal is voluminous, a great number of electronic elements are needed to construct a switching hub. Furthermore, the whole system is organized in a redundant configuration to ensure uninterrupted service. Therefore, the cost performance of the switching hub is low.
Japanese Laid-Open Patent Specification Hei-4-92526 discloses a switch for interconnecting a number of user terminals and multiple service units according to a control signal from a system controller. A bus system is provided in the switch and the system controller uses the LAN technology to send the control signal through the bus to establish connections in the switch and reconfigure its routing pattern in the event of a failure. The system controller thus process all the signals which are routed through the established connections. If the signals are voluminous, a heavy burden will be imposed on the system control, and as a result, it must be operated at a significantly high speed.